PDF(Pubmed)
Abstract：
The types and morphology of sheep horns have been extensively researched, yet the genetic foundation underlying the emergence of diverse horn characteristics during the breeding of polled Tibetan sheep has remained elusive. Genome-wide association analysis (GWAS) was performed on 103 subtypes (normal large horn, scurs, and polled) differentiated from G2 (offspring (G2) of parent (G1) of polled) of the polled core herd. Six single nucleotide polymorphisms (SNPs) located on chromosome 10 of the relaxin family peptide receptor 2 (RXFP2) gene exhibited positive correlations with horn length, horn base circumference, and horn base interval. Furthermore, in genotyping 382 G2 individuals, significant variations were observed for each specific horn type. Three additional mutations were identified near the target SNP upstream of the amplification product. Finally, the RXFP2-specific haplotype associated with the horned trait effectively maintained horn length, horn base circumference, and horn base interval in Tibetan sheep, as confirmed by population validation of nine loci in a sample size of 1125 individuals. The present study offers novel insights into the genetic differentiation of the horned type during improvement breeding and evolution, thereby establishing a robust theoretical foundation for polled Tibetan sheep breeding and providing valuable guidance for practical production.
摘要：
羊角的类型和形态已被广泛研究,然而，在受检的藏羊育种过程中出现多种角特征的遗传基础仍然难以捉摸。对103种亚型（正常大角，scurs,并进行了投票）与被投票的核心牛群的G2（被投票的父母（G1）的后代（G2）区分开。位于10号染色体的松弛素家族肽受体2（RXFP2）基因的六个单核苷酸多态性（SNPs）与角长度呈正相关，喇叭底座周长,和喇叭基地间隔。此外，在对382个G2个体进行基因分型时，对于每种特定的喇叭类型，观察到显着的差异。在扩增产物上游的靶SNP附近鉴定了三个另外的突变。最后,与角状性状相关的RXFP2特异性单倍型有效地保持了角长，喇叭底座周长,和藏羊的角基间隔，如在1125名个体的样本量中对9个基因座的群体验证所证实的。本研究为改进育种和进化过程中有角类型的遗传分化提供了新的见解，从而为受检藏羊育种建立了坚实的理论基础，为实际生产提供了有价值的指导。
